Gaslighting is outrageous behavior from anyone, let alone a U.S. president. Don't get confused, don't get exhausted, and don't stop fighting back.

The United States is in an abusive relationship with the president. As a therapist in clinical practice, I’m trained to spot the signs and offer strategies to help people cope. Abusive relationships are extremely dangerous, and this is no exception. Donald Trump’s gaslighting has led the country into a spiral of doubt, anger and despair.

Gaslighting behavior has always been present in history, to a degree. It is par for the course whenever a person or entity wants to exert as much control as possible over others. But we haven’t seen this level of gaslighting since the Axis powers of World War II.

Consider Trump’s statement: “What you’re seeing and what you’re reading is not happening.” Or this from Rudy Giuliani, Trump’s attorney: “Truth isn’t truth.” This is a classic gaslighting technique — telling victims that others are crazy and lying, and that the gaslighter is the only source for “true” information. It makes victims question their reality, becoming even more dependent on the gaslighter for “truth.”

Republicans who enable Trump are complicit

“If he says he’s going to turn the moon purple I believe him,” said Trump superfan Gene Huber at a rally this summer. And in fact, there is widespread denial among Trump supporters about facts that are perceived as undermining his authority.

On Aug. 21, Trump’s former lawyer pleaded guilty to tax evasion, bank fraud and campaign-finance violations while Trump’s former campaign chairman was convicted on eight counts of bank and tax fraud. At Trump’s rally that evening, the crowd chanted, “Lock her up” — in reference to Hillary Clinton.

Just this week, Trump deployed a classic gaslighting technique when asked whether Supreme Court nominee Brett Kavanaugh would be disqualified if he had lied about or mischaracterized his history with alcohol. Rather than answering the question, Trump said, "There are bad reports on everybody" and launched into accusatory remarks about Democratic Sens. Richard Blumenthal, Cory Booker and Dianne Feinstein.

This is not normal behavior from anyone, let alone the president of the United States. But Trump’s behavior is so continually outrageous that it has been normalized — and mainstream Republicans who fail to call him out for fear of retribution are complicit in constructing this alternate reality.

Dictators and would-be dictators use these same tactics to gain power and control over their constituents. The more gaslighting continues, the more off-kilter and confused the population becomes, until people are too tired to fight back.

What do we do? When we are told something that we obviously know to be untrue, we experience cognitive dissonance. This is when things just don’t “sit right” with us. What we are experiencing is vastly different to our values and what we hold to be true. Pay attention to that feeling — and don’t be afraid to make your voice heard. Contact your representatives. Speak with your vote. Fight voter suppression. Remember, protesting is your constitutional right.

Find the courage to call out gaslighters

When you see gaslighting among your friends, family or colleagues, call it out for what it is. Provide evidence that what a gaslighter is saying and doing is not true. Educate others about gaslighting so that they, too, can start to identify it and call it out. But when you catch a gaslighter, simply present the facts to them, calmly and with purpose. Don’t allow yourself to get baited. Then walk away, shut off your laptop, leave it be.

If you still support Trump, it’s time to take a hard look at your motivation. How has he delivered on his campaign promises? Is he doing anything to make your life better? Are the people and groups he rallies against really harming you? Do you, in your heart, feel proud to call him your president?

I think you already know the answer. In my practice, I’ve seen victims of gaslighting allow the behavior to continue because they don’t want to admit what has been happening all along. Let’s find the courage to call out gaslighters wherever we see them — even if it’s in the Oval Office.

Stephanie Sarkis is an author and psychotherapist. Her latest book, "Gaslighting: Recognize Manipulative and Emotionally Abusive People — and Break Free," was published Tuesday. Follow her on Twitter: @StephanieSarkis‏